A reactor, in this meaning, is a nuclear reactor: a huge, tightly controlled machine that keeps a nuclear chain reaction going so we can make heat, and then electricity. The reaction is happening on purpose, slowly, behind thick walls.

a reactor在這個意思裡 is a nuclear reactor就是核反應爐 a huge, tightly controlled machine一個巨大、受到嚴密控制的機器 that keeps a nuclear chain reaction going讓核連鎖反應持續進行 so we can make heat, and then electricity好讓我們能產生熱、再轉成電 the reaction is happening on purpose, slowly, behind thick walls這個反應是刻意、緩慢地在厚牆後面進行的

Though actually, the same English spelling can also mean a tank where chemicals react, or even a person who reacts — but when people say reactor in the news, they almost always mean the nuclear one.

though actually不過其實 the same English spelling同樣的英文拼法 can also mean a tank where chemicals react也可以指化學反應槽, or even a person who reacts甚至可以指做出反應的人 but when people say reactor in the news但新聞裡說reactor時 they almost always mean the nuclear one幾乎都是指核反應爐

It is not a bomb. A bomb is built to go off all at once. A reactor is built so the same kind of energy comes out little by little.

it is not a bomb它不是炸彈 a bomb is built to go off all at once炸彈是設計成一次全部爆發 a reactor is built so the same kind of energy comes out little by little反應爐則設計成讓同樣的能量一點一點釋放出來

If the control fails, that is when the danger stories you hear about begin.

if the control fails如果控制失敗 that is when the danger stories you hear about begin你聽到的那些危險故事就是這時候開始的